Polymeric shells, including unsupported medical, surgical, and other gloves, are typically made of latex. These polymeric shells are produced in an assembly line fashion by dipping a coagulant-coated former of desired shape into an aqueous latex emulsion, thereby coagulating the latex. The coagulated layer is subsequently cured to form the unsupported polymeric shell. The aqueous latex emulsion may comprise additives, including viscosity modifiers, waxes, surfactants, stabilizers, cross-linking agents and the like, to produce a cured latex product having specific characteristics, such as thickness, tensile strength, tear and penetration resistance, flexibility, etc., in a controlled manner. Aqueous latexes of different compositions are known in the art, and they include natural rubber latexes, synthetic polyisoprenes, and other synthetic latexes, including polychloroprene (i.e., neoprene), nitrile compositions, and the like. Examples of polymeric shells made from a typical aqueous dipping process are described in U.S. Pat. No. 3,268,647 to Hayes et al., which discloses the manufacture of rubber gloves. Nitrile latex gloves are commonly used to provide chemical resistance. Likewise, chemical resistant polymeric shells are commonly made from nitrile latex. The gloves can be provided with skin comfort features such as an open-celled foam lining as described in U.S. Pat. No. 7,048,884 (Woodford), or lined with a flock lining as described in U.S. Pat. No. 7,037,579 (Hassan). Skin-generated moisture is absorbed the open celled foam or flock lining to provide a comfortable feel on the hand of the user.
Supported polymeric shells with a liner are known in the art and are commonly used in industrial environments, such as in the form of gloves for protecting hands, where use of a strong latex product is needed. A number of patents disclose coating the liner with a latex composition. For example, U.S. Pat. No. 2,083,684 to Burke discloses rubber-coated gloves and a method of making the same. U.S. Pat. Nos. 4,514,460; 4,515,851; 4,555,813; and 4,589,940 to Johnson disclose slip-resistant gloves and a method for their manufacture.
Cut resistant liners are also known in the prior art. U.S. Pat. No. 4,526,828 to Fogt, et al. discloses protective apparel material and method for producing same. The protective material comprises a base layer of textile material, an intermediate layer of relatively cut-resistant fiber material, and an outer layer of solid, elastomeric material. The intermediate layer is formed from intermeshing strands of cut resistant materials such as aramid or wire. The intermeshing strands define pores sufficiently large to permit the passage of a dipped elastomeric material while the base layer is sufficiently non-porous to prevent the passage of the dipped elastomeric material. The outer layer of elastomeric material retards penetration by liquid. A cut through the elastomeric layer from a blade tip may penetrate the pores which will result in liquid permeability through the protective glove. Cotton may be a predominant component of the skin-contacting base layer.
U.S. Pat. Nos. 4,779,290 and 4,833,733 to Welch et al. disclose cut resistant surgical glove and the method of making the same. This surgical glove has a ventral side and a dorsal side that are integrally connected by a thin stretchable material layer that is impermeable to air and water. The dorsal side includes a layer of flexible armor embedded in the thin stretchable material. The armor is made from interwoven aramid and nylon fibers. A cut to the thin stretchable layer results in leakage of any liquid contacting the glove and the integrity of the surgical glove is compromised.
U.S. Pat. No. 5,070,540 to Bettcher discloses protective garment having a cover, a fabric liner, and a coating of elastomeric material permeating the cover and adhering the liner and cover together. The fabric liner is in a skin-contacting region. The cover is cut resistant with wire strands. The cover can be knit from yarn that has a core having 2 to 6 strands of stainless steel wire and a parallel synthetic polymer fiber strand, and the core can be wrapped with strands of non-aramid fiber in opposite directions one on top of the other. The elastomeric material can be formed from nitrile latex, which is said to infiltrate the cut resistant cover, but does not infiltrate through the fabric liner, yet infiltrates sufficiently to adhere the liner to the cover. Such precision of latex dipping, however, is not readily realized in industrial practice. Grip on an outer surface of the glove surface is provided by adding pumice to the nitrile latex, which also decreases its impregnating capability into the cut resistant cover. This type of nitrile impregnation is only possible if the cover has knits that are widely spaced, which according to Bettcher, is indicated to be 0.05 inches based on the overall yarn dimension including the core and its wraps. A blade can easily penetrate this wide space between the knits of the cover creating a cut that compromises the impermeability of the elastomeric layer and that permits liquid accumulation. Thus, the protective glove is not damage tolerant.
U.S. Pat. No. 5,581,812 to Krocheski discloses a leak-proof textile glove. The inner surface of a cut-resistant textile layer is bonded to a leak-proof, petroleum-resistant, polymeric material, such as PVC, and the skin contacting side of the leak-proof liner is coated with cotton flock. Any damage to the leak-proof polymeric layer by a sharp object results in leakage of a liquid contacting the glove.
U.S. Pat. No. 5,822,791 to Baris discloses a protective material and a method wherein a base layer comprises cut resistant yarn, an intermediate layer comprises natural fiber, and an outer layer comprises a flexible, elastomeric material impervious to liquid. The intermediate layer is bonded to the elastomeric material, while the cut resistant yarn in the base layer remains substantially free of encapsulation by the elastomeric material. The intermediate layer is joined to the base layer at one or more locations, preferably by selective strike through of limited amounts of the elastomeric material to encapsulate yarn in the base layer. The cut resistant yarn forms the innermost layer of the glove contacting and protecting the hand. However, any damage to the outer elastomeric material results in liquid permeation and thus the material according to Baris does not sustain damage and still protect the user.
U.S. Pat. No. 6,021,524 to Wu et al. discloses cut resistant polymeric films. The cut resistant polymeric films are used for manufacturing medical or industrial gloves and comprises at least three elastomeric layers wherein the middle layer has a three-dimensional network of cut resistant fibers selected from glass fibers, steel fibers, aramid fibers, polyethylene fibers, particle filled polymeric fibers, and their mixtures. The integrity of the cut resistant layer is entirely determined by the character of the network of the cut resistant fibers. Chopped, loose fibers can be moved around especially when encapsulated in a polymeric material such as synthetic or natural rubber and the liquid leak-proof quality of the polymeric film can be easily compromised by a small cut.
U.S. Pat. Nos. 6,543,059 and 6,596,345 to Szczesuil et al. disclose a protective glove and a method for making same. This protective glove for a human hand includes an inner glove of polyester, non-woven, needle-punched material and a melt-sprayed polyurethane coating. This non-woven needle-punched material has no mechanical integrity, unlike a woven or knitted fabric and the hot melt-sprayed polyurethane adhesive holds the configuration together forming a glove. The melt-sprayed glove is heated to a temperature of 300 to 325° F. to allow the remelted polyurethane to penetrate the inner glove to a depth short of penetrating to the inner surface of the inner glove. The polyurethane coating on the outer surface of the inner glove cures in approximately 24 hours by reaction with ambient moisture. The inner glove is further coated with a rubberized material to produce an inner glove held together by the rubber, which is then cut to pieces and sewn, to form a glove with internal sewn seams. Such a glove is not liquid-impervious, since these sewn seams are not bonded and leak. Such a glove is, therefore, not chemically resistant. The protective glove is said to protect from puncture, but the polyester non-woven inner glove will not provide cut resistance. The glove is only leak-proof as long as the polyurethane adhesive layer is not cut and due to the shallow penetration of the polyurethane adhesive coating, it is easy to cut the polyurethane layer.
U.S. Pat. Nos. 6,782,720 and 6,782,721 to Vero et al. disclose unilayer fabric with reinforcing parts. This unilayer flexible textile performance fabric has a base fabric of a predetermined design of a pattern continuously formed by a step of selectively manipulating and chain-stitching on a programmed knitting machine into the base fabric at least one dissimilar high performance fiber into the base fabric in the same layer using a preselected single needle. This selectively reinforced fabric which may have a glove shape has no liquid-impervious latex layer and is therefore not leak-proof.
U.S. Pat. No. 6,918,241 to Zhu discloses cut resistant yarns and process for making the same, fabric and glove. The glove is made by knitting or weaving of a cut resistant yarn comprising polyurethane filament or rubber and a plurality of bulked continuous cut resistant filaments, wherein the plurality of bulked continuous cut resistant filaments have a random entangled loon structure in the yarn. The glove is heat set and a coating of polyurethane or a polynitrile is applied to the glove and cured. The leak-proof quality of the glove relies on the integrity of the polyurethane or polynitrile layer and any damage to this layer results in liquid leakage.
U.S. Pat. No. 7,007,308 to Howland et al. discloses protective garment and glove construction and method for making same. The garment or glove has a cut and puncture resistant protective liner or multiple liners affixed to the inside shell or outside shell of the garment or glove by means of adhesives or stitching. The cut resistant protective liner may be attached to the outer surface of the inside shell by an adhesive layer. Alternatively, the cut resistant liner may be attached to the inside surface of the outside shell by an adhesive layer. When both inside shell and outside shell are present, the cut resistant liner is only attached to the inside shell by an adhesive layer. The liner or the adhesive is not indicated to be leak-proof. The cut resistant liner is not integrally attached to either the inside shell or the outside shell, thus any damage to the outer shell results in liquids leakage. The outer shell does not provide grip properties.
U.S. Pat. Appln. Pub. No. 2006/0068140 to Flather et al. discloses a polymeric shell adherently supported by a liner and a method of manufacture. This glove article has a cured, liquid-impervious polymeric shell that is substantially free from defects, a liner, and a non-tacky, thermoplastic adhesive layer between the shell and the liner. The adhesive layer is melted and solidified to create a non-tacky bond between the shell and the liner. The liner can be moisture-absorbing or cut-resistant and the liner supports and limits stretch ability of the shell, thereby preventing adhesive delamination between the adhesive layer and either of the shell and/or the liner. In one embodiment, the cut resistant liner is outside the liquid-impervious polymeric shell and is bonded by melted and solidified non-tacky polyurethane adhesive. The bond between the shell and the cut resistant liner is generally superficial, that is, the adhesive does not readily penetrate the cut resistant liner. Also, the adhesive used is non-tacky and solid at room temperature, creating a rigid bond between the liner and the liquid-impervious polymeric shell. As a result, upon impact from a blade or the like, there can be free space between the cut resistant liner and the liquid-impervious shell, which can lead to liquid accumulation. This liquid accumulation can reduce the grip properties of the glove since the accumulated liquid acts as a lubricant.
WO Int'l Pub. No. WO2007/024127 to Aaron et al. discloses a method and article of manufacturing a waterborne polyurethane coated glove liner. The process for producing a waterborne polyurethane coated glove liner comprises the compounding of the waterborne polyurethane that is coated on a glove liner using the conventional dipping process of a supported glove. The glove liner to support the glove includes nylon or other synthetic polyamides, polyester, cotton, rayon, Dyneema, Kevlar, Lycra, spandex, acrylic and blended yarns. The polyurethane coating is free of DMF solvent. The waterborne polyurethane coated glove liner is designed to give excellent grip for safe and secure handling. The polyurethane coating is subject to damage by oils and petroleum and is affected by solvents. The contact of polyurethane coating against the hand in a cut resistant fiber may expose sharp ends of the cut resistant liner, thus irritating the skin of the user.
Therefore, there is a need in the art for damage tolerant chemically resistant cut resistant flexible latex glove article that has superior dry and wet grip properties. While handling oily or wet articles, liquid should not accumulate on the surface of the glove compromising glove grip properties. There is a need in the art for a manufacturing process that reliably produces high quality damage tolerant chemically resistant cut resistant gloves on a routine basis at a low cost. These and other objects and advantages, as well as additional inventive features, will be apparent from the detailed description provided herein.